The present invention relates to novel benzopyrans having pharmacological activity, to a process for preparing them, to pharmaceutical compositions containing them, and to their use as smooth muscle relaxants in the treatment of hypertension and urinary incontinence via potassium channel modulation.
Recent reviews of potassium channel modulators are by: Longman et al., Medicinal Research Reviews, 1992, 12, 73; Robertson et al., J. Med. Chem. 1990, 33, 1529; Weston et al., TiPS 1990, 11, 417; and Evans et al., Ann. Rep. Med. Chem., 1991, 26, 73. Ashwood et al. disclose classes of chromans that are described as having blood pressure lowering activity in U.S. Pat. No. 4,616,021 and European Patent Publication 158,923. Quagliato et al. disclose classes of chromans that are described as having blood pressure lowering activity in U.S. Pat. Nos. 4,925,839 and 4,983,612. In addition, Soll et al. disclose a related class of chromans in U.S. Pat. No. 4,908,378. Yamanaka et al. disclose a series of hydrazido and hydrazino substituted chromans as having extremely long acting vasodilatory effects in EP-339,562-A2. Bruneau et al. disclose the synthesis of classes of substituted indazoles in European Patent Application 284,174 A1, although these compounds are described as inhibitors of the enzyme 5-lipoxygenase and thus useful in the area of inflammation.